The 48V mild hybrid system is a mild hybrid technology that achieves energy conservation and efficiency improvement by integrating a 48V lithium battery, a belt-driven starter generator (BSG)/integrated starter generator (ISG), and an energy management module into the architecture of traditional fuel vehicles. Operating at a voltage level four times that of the traditional 12V system, it can recover braking energy and store it in the battery. It provides additional torque to assist the engine when the vehicle starts or accelerates, reducing the comprehensive fuel consumption by 8%-15% under urban road conditions, while significantly improving the smoothness of start-stop (vibration is reduced by 80%) and low-speed power response. However, the 48V battery usually requires a warranty coverage of more than 8 years/150,000 kilometres to reduce the risk of later maintenance. Compared to full hybrid (HEV) or plug-in hybrid (PHEV), the motor of the 48V mild hybrid cannot independently drive the vehicle. It is a transitional solution that balances cost and performance, especially suitable for car owners who drive more than 15,000 kilometres per year and mainly commute in the city. Currently, most mainstream models adopt the P0 topology, which uses a 48V motor to replace the traditional generator, taking into account both modification convenience and energy efficiency improvement. With the advancement of government emission reduction policies, this technology is becoming an important choice for local car companies to comply with environmental regulations.
